<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin: 0;
            padding: 0;
            outline: 0;
        }
        a{
            text-decoration: none;
            color: inherit;
        }
        .pj_tabbar{
            display: flex;
        }
        .pj_tabbar__item{
            flex: 1;
            height: 50px;
            border-bottom:1px solid #ddd ;
        }
        .pj_tabbar__item a{
            display: block;
            line-height: 50px;
            text-align: center;
        }
        .pj_tabbar__item a:first-child{
            border-right: 1px solid #ddd;
        }
        .pj_tabbar__item_on {
            background-color: pink;
            color: white;
        }
    </style>
</head>
<body>
    <div class="pj_tabbar">
        <div class="pj_tabbar__item pj_tabbar__item_on">
            <a href="#" data-type="basic">basic</a>
        </div>
        <div class="pj_tabbar__item">
            <a href="#" data-type="super">super</a>
        </div>
    </div>
    <div id="list">

    </div>
    <script>
        const list=document.getElementById('list');
        const links=document.querySelectorAll('.pj_tabbar__item a');
        const tabTypes={
            basic:Symbol(),
            super:Symbol()
        }
        // Java 等大型语言 tab切换时 为了可读性 会加入tabTypes对象常量
        
        // const tabTypes={
        //     basic:'basic',
        //     super:'super'
        // }

        links.forEach(link=>{
            link.addEventListener('click',function(event){
                event.preventDefault();
                const type=this.dataset.type;
                const parent=this.parentNode;
                if(!parent.classList.contains('pj_tabbar__item_on')){
                    document.querySelector('.pj_tabbar__item_on')
                        .classList.remove('pj_tabbar__item_on');
                    parent.classList.add('pj_tabbar__item_on');
                }
                // if(type == 'basic'){
                if(type == tabTypes.basic){
                    list.innerText='basic';
                }
                if(type == tabTypes.super){
                    list.innerText='super';
                }
            });
        })
    </script>
</body>
</html>